On 29 Feb 2016 15:56, Rich Felker wrote: > I've been trying to use strace on a NOMMU system (sh2) and have been > experiencing an issue where the return value (read from r0) and args > 5/6 (r0,r1) are bogus, making the output much less useful than it > otherwise would be. The problem seems to be that the tracer is > desynced with the child's STOP parity and is confusing syscall > entry/exit, probably due to exec_or_die not stopping itself before > exec to sync with the parent. Even if not for the bug I'm > experiencing, this seems to be problematic in that early syscalls in > the child can be lost (I've actually hit that problem too).
on Blackfin, strace was always flaky beyond the first process. i never got around to tracking it down. > The attached (very hackish at the moment) patch makes it work for me > by eliminating the need to define NOMMU_SYSTEM to 1 and using clone() > with CLONE_VM and a new stack for the child, instead of vfork. I see > some potential issues that need to be addressed before this could be > made into a proper solution, though: > > 1. I'm not sure if all NOMMU systems strace supports have clone. If > so, I think vfork could be dropped completely and this used > instead. uClibc has long required clone, so seems safe to assume it exists -mike
signature.asc
Description: Digital signature
------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
_______________________________________________ Strace-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/strace-devel
